The project belongs to the intersection of civil and ocean engineering disciplines. The common feature of long-span bridges, architectural cables, deep-sea oil pipelines, and deep-sea platform multi-column buoy structures is slender multi-column systems. Under the action of strong ocean currents, the fluid-structure coupling effect and the fluid-induced interference effect between structures in the multi-cylinder system cause structural vibration and fatigue damage. The complexity and strong non-linearity of these effect characteristics and mechanisms have been scientific problems of long-term concern, but the understanding is very limited, resulting in blindness in engineering design and prominent safety hazards; for example, to ensure the safety of deep-sea risers, up to 20% are used.~A safety factor of 40 times, but the safety of the project is still difficult to guarantee. Traditional calculation methods are difficult to reliably simulate the above problems. After more than ten years, the project has established the theory and calculation method for nonlinear fluid-solid coupling effects and flow control analysis of multi-cylinder systems. 1) A high-precision, strong adaptability and stable fluid-solid coupling calculation method is proposed. A new high-order time-accurate characteristic line stabilized fluid finite element algorithm for unsteady flow is constructed, which solves the problem of accuracy degradation or distortion of traditional methods and expands the application scope of the characteristic line method. A high-fidelity mechanical model of fluid-solid coupling based on joint interface coupling conditions is proposed, and a new algorithm for information transfer at the fluid-solid interface is established, which eliminates interface information loss and fluid-solid subdomain calculation asynchronously, improves accuracy and convergence, and enhances Adaptability to extreme situations and overcomes computational divergence. The results were written into the classic textbook of finite element theory by Zienkiewicz, the father of computational mechanics, academician of the Royal Academy of Engineering, and Taylor, academician of the American Academy of Engineering; were selected as the first hottest paper in authoritative journals; and the international journal Int. J Comput. Based on this, the editor-in-chief of Meth and the chairman of the Asia-Pacific Society of Computational Mechanics developed the immersion-smoothing finite element method. 2) The diversity and occurrence conditions of cylinder group flow interference modes (in-phase, anti-phase and oscillating types) and interference phenomena (narrow jet oscillation, shear layer oscillation, etc.) were discovered, and the influence laws and mechanisms of flow interference modes on cylinder flow actuation characteristics and wake topology evolution were revealed, and the influence laws of adjacent structures on the generation and evolution of separated flow in cylinders were discovered. The results serve as a verification benchmark and have been cited by many internationally renowned scholars for correctness and effectiveness testing. 3) A multi-degree-of-freedom fluid-solid coupling mechanical model of the column group under flow interference is constructed, which reveals the motion characteristics of the structure under strong nonlinear resonance (tail-excited resonance/bidirectional resonance), clarifies the characteristics of column-column coupling effects, and discovers the phenomenon of negative effective added mass in two-way resonance of the column system. The results have been widely cited and highly praised in many places by the editor-in-chief of the top journal Ocean Eng., serving as a benchmark for verification. 4) A physical model and quantitative optimal layout of parallel partition plates for flow-induced response drag reduction and vibration reduction of a column system are proposed, revealing the mechanism of drag reduction, vibration reduction and wake control. An active control model for the cylindrical wake is proposed, which reveals the suppression effect and mechanism of the resonant thin plate on the cylindrical wake. It is found that the thin plate achieves drag reduction and vibration reduction by adjusting the flow velocity characteristics of the wake. The results are used as cover papers of journals, and many international scholars have extensively quoted and commented on them as the latest progress in flow control. Published 188 related papers (39 SCI papers and 1 ESI highly cited), with a total of 2361 citations, and a single paper with a maximum of 269 citations (CNKI); the above SCI papers totaled 638 citations. 8 SCI representative works (1 authoritative journal CAS ranked first in the hottest paper, authoritative journal Phys. Fluids cover paper 1) He cited 310 times, SCI 193 times. The numerical platform created based on this achievement has solved many major engineering technical problems such as the National Science Project, the FAST Cable System of the world's largest telescope with a diameter of 500m, and the tallest building in Beijing, ldquo; China Zunrdquo;. Cultivate one leading talent in Shanghai, one national youth scholar, one oriental scholar each, and three excellent books in Shanghai.